1. Field of the Invention
This invention relates to a new and improved container of a thin-walled plastic suitable for yogurt and other dairy products closed with a lid. The container has a tamper-evident band attached thereto by frangible bridges. The upper portion of the band is heated and bent to form an inwardly directed annular projection at approximately a 90.degree. angle to retain the lid so that it cannot be removed without separating the band from the container thereby rendering the container tamper-evident. The invention further comprises the method of bending the band to form the projection.
2. Description of Related Art
The use of tamper-evident bands to retain lids on containers of this general type are known in the art. Letica U.S. Pat. No. 4,711,364 shows such a construction but the lid is held in place by snap action of the lid and the lip on the upper end of the container. In the present invention, the tamper-evident band is heated and bent inward to secure the lid in place. Cooperating locking beads on the lid and container are primarily for re-closure purposes.
Applicants' U.S. Pat. No. 5,163,575 shows a tamper-evident band curled to secure a lid in place. However, the curl of the lid is, in cross-section, of a curvature, approximately 180.degree. or greater, whereas in the present invention the upper portion of the band is formed in an inward directed annular projection which fits on top of the lid.
Curling of plastic cylindrical bands is known in the art. For example, applying a concave tool to the edge of a cylindrical plastic member is shown in numerous patents to Thompson, such as U.S. Pat. Nos. 4,708,255; 4,709,824; 4,793,506; 4,872,304; 4,823,967; 4,811,857; and 4,856,667. These patents disclose a curled bead which is resilient and compressed when a screw closure is applied to a container neck. Similar curling techniques are employed in the present invention, but the resulting annular projection is employed for a totally different purpose and is shaped in a different manner than are the curled beads of the foregoing Thompson patents.